1. Field of the Invention
The invention relates to a vibration generator for a vibration pile driver and to a vibration pile driver.
2. The Prior Art
In construction, vibration generators are used to introduce objects, such as profiles, into the ground, or to draw them from the ground, or also to compact ground material. The ground is excited by vibration, and thereby achieves a “pseudo-fluid” state. The goods to be driven in can then be pressed into the construction ground by a static top load. The vibration is characterized by a linear movement and is generated by rotating imbalances that run in opposite directions, in pairs, within a vibrator gear mechanism. Vibration generators are characterized by the rotating imbalance and by the maximal speed of rotation.
Vibration generators are vibration exciters having a regular linear effect, whose centrifugal force is generated by rotating imbalances. These vibration exciters move at a changeable speed. The size of the imbalance is also referred to as a “static moment.” The progression of the speed of the linear vibration exciter corresponds to a periodically recurring function, for example a sine function, but it can also assume other shapes. The characteristics of the vibration generator can be influenced by way of the static moment, the speed of rotation, and the static top load. These are essential operational characteristic variables for vibration generation. Disadvantageous operational characteristic variables cause a great power loss and a reduction in the efficiency of the vibration generator. In this connection, the amount of the power loss is particularly influenced also by the composition of the penetration medium, i.e. the medium or the ground into which the goods to be driven in are being introduced. In practice, it has been proven to be complicated and problematic to coordinate the operational parameters to the composition of the medium being penetrated.